#include<iostream>
class Base1
{
    public:
    Base1(int a):a(a){}
    void show()
    {
        std::cout << "a:" << a;
    }
    protected:
        int a;
};
class Base2
{
    public:
    Base2(int b):b(b){}
    void show()
    {
        std::cout << "b:" << b;
    }
    protected:
        int b;
};
class Derived
{
public:
Derived(int a,int b):b1(a),b2(b){}
void show()
{
    b1.show();
    b2.show();
}
private:
    Base1 b1;
    Base2 b2;
};
int main()
{
    Derived d(1,2);
    d.show();
    return 0;
}